Explanation

• Protein synthesis is performed by ribosomes, not by the cell membrane.
• The cell membrane controls the movement of substances into and out of the cell.
• It helps in cellular communication through membrane receptors.
• It protects the cytoplasm and separates the internal contents of the cell from the external environment.
• Ribosomes may be free in the cytoplasm or attached to the rough endoplasmic reticulum.

Last verified on 31-10-2026

Explanation

• Natural passive immunity occurs when antibodies are transferred naturally from mother to fetus through the placenta.
• The main antibodies transferred across the placenta are IgG antibodies.
• These antibodies provide temporary protection to the newborn against certain infections.
• The baby receives protection without producing these antibodies through its own immune system.
• Breast milk, particularly colostrum, also provides antibodies (mainly IgA) to the newborn.

Last verified on 31-10-2026

Explanation

• The vertebral column, also called the backbone or spine, is part of the axial skeleton.
• The axial skeleton forms the central supporting axis of the human body.
• It includes the skull, vertebral column, ribs, and sternum.

Additional information:

• The human vertebral column usually consists of 33 vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused), and 4 coccygeal (usually fused).

Last verified on 31-10-2026

Explanation

• Facilitated diffusion uses membrane transport proteins, such as channel or carrier proteins, to move substances from higher to lower concentration.
• This process is a type of passive transport, so it does not require cellular energy (ATP).

Additional information:

• Active transport moves substances against their concentration gradient and usually requires energy.
• Simple diffusion occurs directly through the membrane without transport proteins.

Last verified on 27-10-2026

Explanation

• The cranium is the part of the skull that encloses and protects the brain.
• It consists of 8 bones.
• These include 1 frontal, 2 parietal, 2 temporal, 1 occipital, 1 sphenoid, and 1 ethmoid bone.
• The human skull has 22 bones in total: 8 cranial bones and 14 facial bones.

Last verified on 31-10-2026